Nowadays, a lot of investigations about a polymer electrolyte fuel cell using an alcohol fuel are performed vigorously for a power source of various kinds of electronic apparatuses, such as a mobile device, since a reduction in size and weight of the fuel cell and the apparatus can be easily realized.
A polymer electrolyte fuel cell comprises a membrane and electrode assembly (MEA) in which a solid polymer electrolyte membrane is sandwiched between a fuel electrode and an oxygen electrode. A fuel cell in which a liquid fuel is directly supplied to the fuel electrode is called a direct fuel cell, and the liquid fuel supplied is decomposed into hydrogen ions, electrons and intermediate products by a catalyst held on the fuel electrode. The hydrogen ions migrate to the oxygen electrode through the solid polymer electrolyte membrane and the electrons are transferred to the oxygen electrode through an external load. The hydrogen ions and electrons react with oxygen in the air on the oxygen electrode and generate an electric power. For example, reactions indicated as chemical equations (1) and (2) occur on the fuel electrode and the oxygen electrode, respectively, in a direct-methanol fuel cell (hereinafter called DMFC) that uses an aqueous methanol solution directly as a liquid fuel.[Chemical equation 1]CH3OH+H2O-->CO2+6H++6e−  (1)[Chemical equation 2]6H++6e−+3/2O2-->3H2O  (2)
Related Patent Documents are as follows.
[Patent Document 1]
    JP Utility Patent Kokai Publication No. U63-5506[Patent Document 2]    JP Patent Kokai Publication No. JP2004-95376A[Patent Document 3]    JP Patent Kokai Publication No. JP2006-59624A[Patent Document 4]    JP Patent Application No. 2006-007657 (Gazette of International Publication No. W02007/080763)[Patent Document 5]    JP Patent Kokai Publication No. JP2006-278159A